Back in the 1970s, sea turtles were already in serious trouble—listed as endangered or threatened under the Endangered Species Act because people were hunting them. But once that direct harvesting mostly stopped, the big new killer became accidental bycatch in shrimp trawls. These turtles would get scooped up in the nets, trapped, and basically drown since they couldn't get back to the surface for air. That's when everyone realized we needed a way to let turtles escape without ruining the shrimp catch, and that's where Turtle Excluder Devices (TEDs) came in. These are basically clever grid setups in the nets that let the turtles swim out while keeping the shrimp inside.
The early TEDs were a bit of a trial-and-error adventure starting around 1976. Some folks got the idea from watching turtles try to escape nets—they naturally push upward—so they built these barriers. The first versions only saved about 30% of the turtles and let too much shrimp escape, which obviously didn't win over the shrimpers. But after tweaking things (like flipping the barrier direction and borrowing ideas from jellyfish excluders), they hit a sweet spot by the early '80s: up to 97% turtle escape rate with hardly any shrimp loss. Netmakers like Billy Burbank helped refine them based on real turtle behavior. They even tried a voluntary program, but most shrimpers weren't on board because the devices felt bulky or heavy at first. So eventually, it had to become mandatory.
Federally, rules kicked in around 1987 for bigger boats in offshore waters (with shorter tow times as an option for smaller ones), but man, it was a fight—lawsuits, court injunctions, protests, even TEDs getting burned in demonstrations. Florida moved faster with emergency rules in 1989 for their nearshore waters, and despite legal challenges (one went all the way to the state Supreme Court), they stuck. There was also this cool import ban starting in 1989—no shrimp from countries that didn't protect turtles—which helped level the playing field for U.S. shrimpers using TEDs. Fast-forward, and these regs have slashed turtle bycatch deaths from shrimp trawling by about 94% since 1990. Pretty solid win for conservation!
There is a great long form article on this topic on the Sea Turtle Conservancy website here. It's a very interesting read. The article teases Part II, which gets into gill nets and long-lines in Florida—sounds like more drama ahead.